Welcome to our resource for MG Car Information.



MG parts spares and accessories are available for MG T Series (TA, MG TB, MG TC, MG TD, MG TF), Magnette, MGA, Twin cam, MGB, MGBGT, MGC, MGC GT, MG Midget, Sprite and other MG models from British car spares company LBCarCo.

MG TD TF 1500 - .012/.019 & .015 ?

I have started to rebuild our TD motor that we got last fall. The valve cover has a .015 brass tag. Reading all the parts books, there is nowhere mentioned this valve setting, just .012 & .019. Does anyone know how this is possible. It is a correct TD valve cover and the the old pistons are just .010 over with 30K+ original miles on it? THX Jack

Jack - The valve cover (or even the whole engine) could well be from another car, such as a Wolesley or a Y type MG with different valve settings. The two valve settings for the T series MG were either 0.019" or 0.012", depending on the cam that is in the engine. Our 53 TD came to us in 74 with a valve cover that had a tag showing 0.015" valve setting on it. It was just recently that I found a valve cover with the correct 0.012" tag on it. Cheers - Dave
David DuBois

John Twist in his you tube series suggests a .015 setting for T types...not sure wht...i still use .012...anyone know why Mr. Twist uses .015?
R Dougherty

Sorry, I did forget to mention this is a matching numbers cars, so the engine is correct to the chassis. I never thought about the valve cover being used on another type of car such as a Y-type. Just maybe this is correct for that series. How could I find out for sure if that is the case, or who would know ? Where on earth would I now find a correct valve cover? THX Jack

My TD has a YA type engine (SC16458) which has a valve cover that states 19 thou gap.According to the experts there is no difference to the engine except the manifold. Other cams were fitted perhaps yours is non standard. Some information from Bob Marshal (see recent thread)says the early cam was AAA5776 (19) and later ones AAA3096 (12) Don't know if the numbers are stamped on the cam shaft but if yiur engine is stipped you may be able to find it.
j c rathbone

Jack, My TD #1720, came with a Y type replacement engine with the plate stating 19 and I used to set it at that 40 years ago. Very noisy. When engine was rebuilt by Dave Raymond 30 years ago it appears he changed plate or cover to one stating 12. As I just finished my break in (500 miles), plan on doing the oil change, retorqueing the head, and resetting the valves. So I am curious as to why J.Twist sets them at 15? Anyone have a comment? (it was a 38 year restoration, by the by). Bob
R.AF. Robert Finucane

I recall John feels that 19 is too loose (frequently with rocker arm wear, etc. is actually greater if you checked it with a dial indicator), and 12thou too tight- risk of burned exhaust valves and decreased performance. Neil Carins-" Running a .019 cam with .012 gaps wil loose power, whereas running a .012 cam with .019 gaps will sound like a diesel engine, by now very few .019 original cams exist" By now, it would be doubful the cam is an original one. Most of the Crane- Moss and Abingdon- cams are set to .018-.020 I think. Valve covers and plates are aviable from Abindon spares, and are often on ebay. Maybe there was some oddball orginal factory cam? An aftermarket cam placed at some prior rebuild? George
George Butz

Jack - e-mail me at the above address and I will send you a procedure for determining which camshaft you have without disassembling the engine. Cheers - Dave
David DuBois

Thanks to all that took the time to reply, guess I must have an odd ball cover. With all the collective knowledge out there, this one must have stumpped everyone, just my luck ! ! Thnxs again. Jack

I also have a cover tag marked .015 on my '53 TD.


L Karpman

Think the last time i set them, i did about 13 or 14... always thought it was 12 loose...figure loose is about 13?
gblawson (gordon)- TD#27667

I always use a 12 & a 14 feeler gauge and adjust so the 12 passes right through and the 14 won't go at all. all of this lose and tight with a feeler gauge passes me right by. The go - no go is much more to my liking (and expertise). Cheers - Dave
David DuBois

Jack Might have cover or tag you need-let me know which you need and I'll check my spares. Dan Craig
D.R. Craig

The cam card from my Crane (Moss) cam says .018 intake and .020 exhaust with the engine hot. The workshop manual says to add .001 for cold engines.

I would get with Dave to find out which cam you have and set accordingly...
Evan Ford - TD 27621

All got my curiousity up, and as I stated my TD came with .019 on the valve cover, was a y engine replacement. I just went down to check on valve cover on parts car, no number stamped or plate, but the valve cover states .019 to set valves! Is it possible that I ended up with two Y engines by chance? They didn't make as many as TD's, so what are the chances?
Also found two camshafts which look identical, but where do you find the parts number? Scanned with 62 year old eyes and found nothing. Going to eye doctor friday for second cat rack surgery. Bob
R.AF. Robert Finucane

I have tried all settings from .012 to .022 and while it makes sense to me that this should affect power, I was never able to notice any difference. Not even in noise!
Denis L. Baggi

John Twist rebuilt my engine and installed a Crane Cam and I questioned him regarding the .015 and he said to use the Cam card specs. BTW I met John at the Carlisle Pa show this past weekend - a nice guy!

tw hager

This thread was discussed between 18/05/2008 and 20/05/2008

MG TD TF 1500 index

This thread is from the archive. The Live MG TD TF 1500 BBS is active now.